Abstract
Purpose: :
To investigate if good correlation exists between novel objective Spectral-Domain Optical Coherence Tomography (SD-OCT) optic nerve head (ONH) parameters and clinical parameters in normal and glaucoma patients.
Methods: :
There were eleven patient volunteers. Included were two normal eyes, two ocular hypertension eyes, two glaucoma suspect eyes, and ten glaucomatous eyes with various stages of glaucoma. A clinical SD-OCT system was used for high-speed (29 fps) and high-axial resolution (4.7 µm) cross-sectional optic nerve head imaging. The SD-OCT neuroretinal rim minimum distance band (MDB) was defined as the circular band with the smallest area delimited by the retinal pigment epithelium (RPE) end and the ONH surface. The mean thickness and area of the MDB were compared with Humphrey visual field (Carl Zeiss Meditec, Dublin, CA) mean deviation (MD) and pattern standard deviation (PSD) and disc photography vertical cup-to-disc ratio assessments (as determined by 5 masked glaucoma specialists).
Results: :
SD-OCT images with MDB determinations demonstrated glaucomatous structural changes that correlated well with visual field test results (Figure 1) and disc photography cup-to-disc ratio assessments. Excellent correlations were found between MDB mean thickness and all clinical parameters [i.e. MD (R=0.631, P=0.009); PSD (R=-0.866, P=0.0004); and cup-to-disc ratio assessments (R=-0.883, P=0.0003)] as well as between MDB area and all clinical parameters [i.e. MD (R=0.633, P=0.009); PSD (R=-0.734, P=0.001); and cup-to-disc ratio assessments (R=0.559, P=0.024)].
Conclusions: :
The objective SD-OCT MDB mean thickness and area calculations correlated very well with the more subjective clinical parameters derived from visual field testing and disc photography and may potentially be used for a more thorough evaluation of glaucoma patients.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)